Each year, sales of artificial holiday trees increase, as more consumers come to see them as more convenient or a better choice for environmental sustainability. Having an artificial tree avoids the need to shop for a live tree every year and the associated cost of a fresh tree. Furthermore, artificial trees need no water to keep them green, and they generate less mess from dry needles.
The effort to buy and set up a live tree every year is a chore. The percentage of consumers who prefer artificial trees compared to live trees is increasing as the percentage of the population over 50 increases. Artificial Christmas trees are easier to assemble and disassemble, especially as many artificial Christmas trees can be purchased with built-in incandescent or LED lighting, which does not have to be removed and rolled up. Also, having an artificial tree means that there is no live tree to cut down or dead tree to dispose of.
Artificial holiday trees are usually made in sections so the trees can be taken apart for ease of storage. The cores of the artificial Christmas trees are typically made of sections of steel tubing. Each tube section has two ends: one male end and one female end, so one end of the next section can be easily inserted into the previous section to assemble the tree.
Each section must also be connected electrically to the next section. Power plugs on the lower end of a next section have to be mated to the correct plugs on the upper end of a previous section in order for all lights on the tree to work properly. This is especially important for trees that have special lighting effects. Assembling artificial tree sections often poses a challenge for consumers.
In most artificial Christmas trees, electrical wires run through the center of each tube section. As sections are joined, internal electrical connectors are aligned and connected automatically to simplify the assembly process. However, in order to align the connections, large manufacturing tolerances are provided so mating contacts do not jam, bend, short out, or break. Unfortunately, large tolerances can cause arcing when the artificial Christmas tree is moved, including movement caused when decorating the tree with ornaments, extra lights, tinsel, etc. Decorating often requires bending and spreading the limbs of each section in shaping the tree to look natural, in stretching and fluffing limbs that were flattened in the course of packaging or shipping the tree, and in adjusting the limb tips to hold special decorative ornaments. While decorating and shaping the tree, it is not unusual to see the tree section lights to flash on and off. This flashing occurs due to poor electrical design that fails to compensate for this movement.
In manufacturing, the wire harness of the core wire system requires considerable time and labor to assemble and then to install from the proximal end of the metal tube to the distal end, all the while extracting wires from the wire harness through holes in the tube for supplying power to the limb sections for the lights they carry. This is a difficult and arduous task, and takes at least as much time as it does to wrap limbs with lights. There is also the complicating factor of assuring that no wire insulation is cut or scraped during the process of assembly. However careful the worker is, there is always the possibility that a wire with a break in its insulation could short against the steel interior of the metal tube section, and thereby electrifying the entire tree, a very dangerous situation.
Still, another problem of prior art artificial trees is the manner in which the tube sections are joined. Essentially, one tube section slides into or over the next tube section. As one tube seats with the next, the two sections make electrical contact. The contacting terminals are located in the center of that tube section.
Prior art tube mating assemblies fit tightly to prevent arcing of the electrical contacts. The extruded tubing is passed through a hydraulic die system to flare one end and compress the other. The outer diameter of the compressed end of one tube section fits into the flared end of the next tube section. Depending on the source of the tubing, however, some sections might fit loosely and other sections, very tightly. After a few years of use, tube sections either become too loose or, if they are tight to begin with, the flared end would scrape the paint off the metal on the compressed end. Rust would then begin to accumulate, resulting in “rust-welding” of the sections. Accordingly, tube sections become either far too loose or far too difficult to separate, especially in the case of taller artificial trees.
In the case of loosely fitting tree tube sections, moving the assembled and decorated tree would cause the sections to separate, often resulting in broken ornaments. Even bending and shaping the steel “limbs” to make the tree appear more natural could cause sections to separate as well, particularly if the limbs are bent upwards.